<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8"></meta>
        <title>js</title>
        <link rel="css/1.css"></link>
    </head>
    <body>

        <button id="btn">点我</button>
        <script src="../../javascript/Class/later/c3.js"></script>
    </body>
</html>